Of heat, cold , light, water

Of heat, cold , light, water , and other factors harmful to insect larvae in their breeding and nesting ; > Biology — the use of natural enemies of pests , such as frogs ; > Chemical — the use of chemical agents. Arahnozy This parasitic diseases which are due to temporary or permanent parasites of class arachnids : real or acariform , mites and ticks . The former include sarkoptoidnye ( scabies ) and demodectic ( Zheleznitsa ) ticks, the second — the ticks . Common scab ruminants Common scab ruminants or nakozhnikovaya scabies — invasive disease caused by mites sarkoptoidnymi thriving on the skin of animals (Fig.

20) . Fig . 20. The female mite — common scab pathogen Ticks are parasites on the skin surface , so they are called nakozhnikami . They feed on cell sap and lymph. In the development distinguish the following stages: egg, larva , protonymph , teleonimfa and adults . The entire development cycle lasts 20-25 days.

Each stage lasts 4-5 days. The larva differs from the other stages that her three pairs of limbs , and nymphs no genital opening . Mites live on the skin of animals up to 2 months . Disease is widespread in all categories of farms , and recorded mostly in the stall period .

At this time in the buildings there is overcrowding of animals , increasing contact between them , increased humidity and creates the conditions for the development of mites. The disease most often observed in farms with poor conditions and feeding animals. Most suffer from depleted animals with low resistance . The main source of infestation are sick animals . The incubation period lasts from 10 to 14 days , and young animals — up to 1.5 months .

The most characteristic symptom is itching in the back, lost sheep fleece.